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G. M. LITTLE. STARTING DEVICE FOR ARC LAMPS. APPLICATION man MAY 11. m4.

Patented July 1, 1919.

WITNESSES INVENTOR 'llll mun-IA PLANOOIAPH 00., WASHINGTON. D. c.

UNITED STATES PATENT OFFICE- GEORGE M. LITTLE, QF PITTSBURGH, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC AN D MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

STARTING DEVICE FOR ABC-LAMPS.

Specification of Letters ratent.

Patented J n1} 1, 1919.

Application filed May 11, 1914. Serial No. 837,730.

To all whom it may concern:

Be it known that I, Gnousn M. LITTLE, a citizen of the United States, and a resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Starting Devices for Arc-Lamps, of which the following is a specification.

My invention relates to are lamps, and particularly to lamps in which insulating deposits form upon the arcing ends of electrodes and thereby interfere with ready starting of the arc.

One object of my invention is to provide simple and reliable means for causing the electrodes of arc lamps to move into and out of engagement for the purpose of removing the insulating deposits from the arcing ends of the electrodes.

Arc lamps are usually provided with electrodes that contain materials which render the same less readily consumable than the ordinary carbon electrodes, and which produce arcs of great luminosity by imparting to the arcs characteristics which greatly enhance their light-giving qualities. A suitable composition for an electrode of this character comprises magnetic oxid of iron as the predominant constituent which gives conductivity to the electrodes, chromium oxid which, by reason of its very high fusing point, assists in preventing ra id consumption of the electrodes and flic ering of the arc, and titanium oxid or some other compound of titanium which imparts color and brilliancy to the arc and also assists in prolonging the life of the electrodes. These impregnating substances can be vaporized at high temperatures only, and form deposits upon the electrodes after having passed into the are. On cooling of the slag, insulating films sometimes prevent the cooperating electrodes from coming into electrical contact with each other, thus rendering it impossible to draw an are between the electrodes at the starting operation of the lamp.

In order to insure sufiiciently good electrical contact between the electrodes to permit ready starting of the arc, it is obvious that the slag or soot must be removed from the arcing ends of the electrodes. This may be accomplished by rapidly moving the electrodes into and out of engagement with one another. The means heretofore provided for effecting these results have usually been complicated and expensive, and have embodied parts requiring accurate adjustment.

My'invention may best be understood by reference to the following description and the accompanying drawing in which the single figure is a view, partially in section and )artially in elevation, of an arc lamp emodying a form of my invention.

A movable upper electrode 1 cooperates with a stationary electrode 2 to maintain an are between the opposing ends thereof. Inasmuch as the lower electrode 2 is stationary, the arc-regulating functions and the feeding operation of the lamp must be performed in connection with the upper electrode 1. A holder or clutch rod 3, which engages the upper electrode 1 by means of a clutch 3 is pivotally connected, at the point 4, through a link 5, to a ratchet wheel 6. A rack 7, cooperatively engaging the ratchet wheel 6, is pivotally secured to the lower end of a plunger 8 which coacts with an electromagnet 9, the rack 7 being provided with a weight 7, which normally holds the rack against the wheel 6. The ratchet Wheel 6 is firmly secured to a wheel 10 of comparatively large diameter which is adapted to rotate about the axis of the wheel 6. A weight 12 is secured to the outer periphery of the wheel 10 to insure the return of the ratchet wheel 6 to its normal position when the electromagnet 9 is denergized. In order to impart a reciprocatory motion to the holder 3, when the plunger 8 is drawn upwardly by reason of the energization of the electromagnet 9, the pivot 4 is eccent-rically disposed upon the wheel 6, with respect to the axis of rotation 11 of the wheel 6.

When the lamp is connected to a supply circuit 17 by closing a switch 18, the electro magnet 9 becomes energized and draws the coacting plunger 8 and the rack 7 upwardly, thereby effecting rotation of the ratchet wheel 6 and the wheel 10, which will rotate several times because of the momentum of the wheel 10. A reciprocatory motion is imparted to theholder 3, by reason of its eccentrically pivoted connection to the wheel 6, which causes the electrode 1 to rapidly engage and disengage the electrode 2. i The clutch 3*, with each of the recurring downward movements imparted thereto bya single actuation of the electromagnet 9, engages a stop member 16, and, in case the electrode 1 has been partially consumed, the first of llO the said movements permits the latter to feed into engagement with the electrode 2. \Vith each of the subsequent downward movements of the clutch caused by the aforesaid single actuation of the eleotromagnet 9, the electrode 1 is similarly released from the clutch but is picked up thereby at the point from which it is released. As the electrode 1 is brought into and out of engagement with the electrode 2, the insulating film formed upon the arcing ends of the electrodes will be broken to permit sufficient current to flow through the electrodes to draw the are. A cut out switch 19 now deenergizesthe electromagnet 9 which pernnts the core 8 to descend and lock the wheel 10 against further rotation, as will be hereinafter explained. A longitudinally extending slot 13 is preferably cut in the lower portion of the link 5 in order to allow flexibility in the movement of the electrode 1.

After the arc has been established, the ratchet wheel 6 returns to its normal position, as shown in the drawing, by reason of the weight 12 being disposed on the periphery of the wheel 10. A pin 14, projecting from the face of the wheel 10, engages an arm 15 that projects laterally from the core 8. This engagement prevents the core 8 from descending beyond a certain predetermined point. and maintains the core in a fixed relation to the electromagnet, so that it may be actuated at a succeeding starting operation of the lamp.

While I have described, somewhat in detail, a starting mechanism embodying a form of my invention, as applied to a particular type of lamp, it will be understood that modifications may be made without departing from the spirit of the invention and the scope of the appended claims.

I claim as my invention:

1. An arc lamp comprisinga rotatable member, an electrode holder eccentrically and pivotally supported by the same, and means responsive to a single impulse effecting rotation of the said member and recurrent engagement of cooperating electrodes.

2. An arc lamp comprising a rotatable ratchet wheel, an electrode-supporting mem ber eccentrically and pivotally supported by the same, and means for rotating the ratchet wheel to effect recurrent engagement of cooperating electrodes.

3. An arc lamp comprising a rotatable ratchet wheel, an electrode-supporting member eccentrically and pivotally supported by the same, a rack for the ratchet wheel, elec- 5. In an arc lamp, the combination with electrodes, of a rotatable ratchet wheel, a holder eccentrically and pivotally supported by said wheel and engaging one of the electrodes, a ratchet bar for cooperatively engaging the ratchet wheel, and an electromagnet for moving the rack upwardly during the starting operation of the lamp.

6. In an arc lamp, the combination with electrodes, of a rotatable ratchet wheel, a

ratchet bar, a holder eccentrically and pivotally supported by said wheel and engaging one of the electrodes, an electromagnet for moving the ratchet bar upwardly during the starting operation, and means for returning the ratchet wheel to a definite position after the arc is drawn.

7. An arc lamp comprising a rotatable ratchet wheel, an electrode holder eccentrically and pivotally supported by the same, a rack for the ratchet wheel, and electromagnetic means for engaging the said ratchet wheel and its rack to strike an are between cooperating electrodes.

8. An are lamp comprising a rotatable ratchet wheel, an electrode holder eccentrically and pivotally supported by the same, a rack for the ratchet wheel, means causing the said rack to impart a rotative movement to the said ratchet wheel, and means for normally holding the said ratchet wheel in a predetermined position with respect to its axis under non-operative conditions and for returning it to the same position at the cessation of the said rotative movement.

In testimony whereof, I have hereunto iglilsicribed my name this 30th day of April GEORGE M. LITTLE.

Witnesses:

PHILLIPS THOMAS, B. B. HINES.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

